[ot/ft] Implement get_nominal_glyphs() callback
Some more measurable speedup. The recent commits' speedups are as follows:
Testing with Roboto, ****when disabling kern and liga****:
Before:
FT --features=-kern,-liga
user↦ 0m0.521s
OT --features=-liga,-kern
user↦ 0m0.568s
After:
FT --features=-liga,-kern
user↦ 0m0.428s
OT --features=-liga,-kern
user↦ 0m0.470s
So, 17% speedup.
Note that FT callbacks are faster than OT these days since we added an advance
cache to FT. I don't think the difference is enough to justify adding a cache
to OT.
When not disabling kern, the thing is three times slower, so the speedups
are three times less impressive... Still, 5% not bad for a codebase that I
otherwise thought is optimized out.
Note that, because of this and other optimiztions in our main shaper,
disabling kern and liga, the OT shaper is now *faster* than the fallback
shaper. So, that's my recommendation to clients that need the absolute
fastest...
diff --git a/src/hb-ot-font.cc b/src/hb-ot-font.cc
index 686c873..1498911 100644
--- a/src/hb-ot-font.cc
+++ b/src/hb-ot-font.cc
@@ -51,6 +51,29 @@
return ot_face->cmap.get_relaxed()->get_nominal_glyph (unicode, glyph);
}
+static unsigned int
+hb_ot_get_nominal_glyphs (hb_font_t *font HB_UNUSED,
+ void *font_data,
+ unsigned int count,
+ const hb_codepoint_t *first_unicode,
+ unsigned int unicode_stride,
+ hb_codepoint_t *first_glyph,
+ unsigned int glyph_stride,
+ void *user_data HB_UNUSED)
+{
+ const hb_ot_face_data_t *ot_face = (const hb_ot_face_data_t *) font_data;
+ const OT::cmap_accelerator_t &cmap = *ot_face->cmap.get_relaxed ();
+ unsigned int done;
+ for (done = 0;
+ done < count && cmap.get_nominal_glyph (*first_unicode, first_glyph);
+ done++)
+ {
+ first_unicode = &StructAtOffset<hb_codepoint_t> (first_unicode, unicode_stride);
+ first_glyph = &StructAtOffset<hb_codepoint_t> (first_glyph, glyph_stride);
+ }
+ return done;
+}
+
static hb_bool_t
hb_ot_get_variation_glyph (hb_font_t *font HB_UNUSED,
void *font_data,
@@ -187,6 +210,7 @@
hb_font_funcs_set_font_h_extents_func (funcs, hb_ot_get_font_h_extents, nullptr, nullptr);
hb_font_funcs_set_font_v_extents_func (funcs, hb_ot_get_font_v_extents, nullptr, nullptr);
hb_font_funcs_set_nominal_glyph_func (funcs, hb_ot_get_nominal_glyph, nullptr, nullptr);
+ hb_font_funcs_set_nominal_glyphs_func (funcs, hb_ot_get_nominal_glyphs, nullptr, nullptr);
hb_font_funcs_set_variation_glyph_func (funcs, hb_ot_get_variation_glyph, nullptr, nullptr);
hb_font_funcs_set_glyph_h_advances_func (funcs, hb_ot_get_glyph_h_advances, nullptr, nullptr);
hb_font_funcs_set_glyph_v_advances_func (funcs, hb_ot_get_glyph_v_advances, nullptr, nullptr);
